From publisher blurb:
Operating from the shadows and fog of the game world, manipulating underlings and the unknowing alike, recurring villains can add depth to any campaign. Hints and clues of the villain’s existence builds to a climactic battle against an opponent that the PCs may have never met before the final scene of the campaign.
For those gamemasters who seek to stitch a common thread through multiple game sessions, the twelve villains that follow may provide inspiration that transforms what could have been a few weeks of lightly-connected adventures into a powerful narrative that the players are unlikely to forget.